Minimum Tree Size Characteristics
Product Pine Hardwood
Pulpwood 6” DBH to a minimum 6” DBH to a minimum
3” top diameter 3” top diameter cord very low
Chip-n-saw 9-14” DBH to a not applicable
minimum 6” top diameter cord low
Sawtimber 14” DBH to a minimum 16” DBH to a minimum
8” top diameter 10” top diameter board foot high
Veneer log 16” DBH, clear/straight 18” DBH, clear/straight
first log first log board foot high
Pilings various specifications not applicable
based on local markets board foot high
Estimating the Volume of a Standing
Tree Using a Scale (Biltmore) Stick
Distributed in furtherance
of the Acts of Congress
of May 8 and June 30, 1914.
Employment and program
opportunities are offered to
all people regardless of
race, color, national origin,
sex, age, or disability. North
Carolina State University,
North Carolina A&T State
University, U.S. Department
of Agriculture, and local
governments cooperating.
The volume of wood in a tree and the type of
product made from the wood are based pri-marily
on the tree’s height and diameter. One
of the basic tools for estimating the height and
diameter of standing trees is a calibrated 25-
inch scale stick, often referred to as a Biltmore
stick or a cruiser’s stick. With practice, this
instrument can be used to provide a reliable
estimate of tree height and diameter, which
then can be used to determine tree volume.
This publication is for those interested in
learning how to estimate tree volume and the
type of product the tree may provide. For
instructions on how to make your own scale
stick, see page 3.
If you want to estimate tree volume in
order to sell timber, it is highly recommended
that you consult a forester for advice. Vol-ume
alone does not determine value or the
products that could be produced; tree quality
is also very important. Forestry consultants
can advise you on the types of wood prod-ucts
that could come from your timber as well
as the quality of your timber. They also can
provide you with estimates of the volume
and value of the timber. In most cases the
consulting forester’s experience with timber
sales and knowledge of current markets can
increase your revenues far in excess of the
forester’s fees. For more information on con-sulting
foresters, visit a county Cooperative
Extension Center or North Carolina Division
of Forest Resources county office.
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Table 1. Minimum tree size characteristics, volume units, and relative value by timber product.
Volume
Unit
Relative
Value
Crop Tree Management in North Carolina 2
Product Types and Measurement Units
Major products that can be produced from pine trees
include pulpwood, chip-n-saw, sawlogs, veneer logs
(also known as plylogs), and pilings or poles. Major
products produced from hardwood trees include pulp-wood,
sawlogs, and veneer logs (also known as grade or
export logs). Each of these products must meet certain
minimum size requirements (Table 1), and each varies in
value based on the product, tree quality, and markets.
For example, a tree 14 inches in diameter (measured
4½ feet above the ground) and with 50 feet of merchant-able
height can produce any one of three products that
will vary in value based on the product (Figure 1).
Standing trees or portions of trees sold for pulpwood
or chip-n-saw are measured in cord volume. A cord is a
stack of 4-foot long pieces of wood that is 4 feet high and
8 feet long; it includes 128 cubic feet of wood, bark, and
air space.
Standing trees sold for sawlogs or veneer logs are
measured in board-foot volume. A board foot is 1 inch
thick, 12 inches wide, and 1 foot long. To determine the
cord or board-foot volume of a tree, first measure the
diameter and height using a scale stick. Check the
diameter at a point 4½ feet above the ground (diameter
breast height or DBH) on the uphill side of the tree and the
merchantable height in increments of 16-foot and addi-tional
8-foot logs. With these two measurements, you
can determine the volume of the tree from various tree
volume tables. Most scale sticks have the International
¼-inch, board-foot volume tables imprinted on them. A
set of volume tables for pines for all three log rules—
International ¼-inch, Scribner, and Doyle—may be found
in Handy Tables for Measuring Farm Timber, Coopera-tive
Extension Service publication AG-119.
In North Carolina, pine sawtimber volume is often
estimated using the Scribner log rule, and hardwood
sawtimber volume is often estimated using the Doyle log
rule. Tree volume estimates will differ based on which log
rule is used because of differences in the way the
estimates were formulated. Using the International ¼-
inch rule as the basis for the volume, the Doyle log rule
provides the lowest estimates for trees up to 30 inches
DBH, and Scribner provides intermediate estimates
across all tree diameters (Figure 2). No matter which log
rule is used to estimate volume, it is important to under-stand
that timber prices also vary with log rules.
Figure 2. Relationships among three log rules in board-foot
volume estimates for trees using the International
¼-inch rule as a standard for comparison.
Figure 1. Relative value of a tree 14 inches in diameter DBH and 50 feet in merchantable height, based on
various products that could come from it.
0%
20%
40%
60%
80%
100%
10 14 18 22 26 30
Tree Diameter (inches)
Percent
Doyle Scribner Doyle Scribner IntIentrenrnaatitoionnaall 1¼/4--iinncchh
14 inches
DBH
50 feet
merchantable
height
Woodland Owner Notes
or
or
Potential Product Volume Relative Tree Value
Pulpwood $3.00
0.23 cord
Chip-n-saw $13.00
0.23 cord
Sawtimber $35.00
145 board feet
Crop Tree Management in North Carolina 3
Making a Scale Stick
Materials
• a yardstick, 1 inches wide
• scissors
• paintbrush
• sandpaper
• rubber cement or a waterproof,
clear household cement that
adheres well
• varnish
Steps
1. Cut out the three paper forms to the
left.
2. Glue Form 1 to the left edge of the
yardstick, making sure that the left
edge of Form 1 is even with the left
end of the stick. The glue should be
placed on the stick.
3. Glue Form 2 to the stick. Make sure
the left edge of Form 2 butts against
the right edge of Form 1, which is
marked by two arrows. The glue
should be placed on the stick.
4. Glue Form 3 to the stick by aligning
the left edge of Form 3 with the right
edge of Form 2, which is marked by
two arrows. The glue should be
placed on the stick.
5. After gluing the three forms to the
stick, trim and sand the corners of
the stick so that the edges are
smooth. Then cover the stick with
clear water repellent (such as a
clear varnish) to protect the stick
during use.
¼8
Crop Tree Management in North Carolina 4
Figure 4A. Measuring merchantable height with a scale stick.
Scale stick at stump height.
Scale stick indicating a
merchantable tree height of
two 16-foot logs.
Measuring Diameter
Tree diameter is the most important measurement of
standing trees. Trees are measured 4½ feet above
ground-level, a point referred to as diameter breast
height or DBH. Diameter breast height is usually mea-sured
to the nearest inch; but where large numbers of
trees are to be measured, 2-inch diameter classes are
used.
To measure DBH, stand squarely in front of the tree
and hold the scale stick 25 inches from your eye in a
horizontal position against the tree at 4½ feet above the
ground. Shift the stick right or left until the zero end of the
stick coincides with the left edge of the tree trunk.
Without moving your head, read the measurement that
coincides with the right edge of the tree trunk. This
measurement is the tree’s DBH, including the tree’s bark
(Figure 3). On sloping ground, measure from the uphill
side. Two measurements at right angles to each other
and averaged will give a more accurate reading since
many trees are not perfect cylinders.
Measuring Merchantable Height
Merchantable height refers to the length of usable tree
and is measured from stump height (1 foot above ground)
to a cutoff point in the top of the tree. The cutoff height will
vary with markets, with the product being produced, and
with the presence of excessive limbs. The scale stick
has been calibrated so that if you stand 66 feet from the
tree being measured and hold the stick 25 inches from
your eye in a vertical position, you can read the number
of merchantable logs from the stick. It is important not to
move the stick when taking a measurement; tilt your
head back slightly so that you do not have to move your
head when reading from stump point to cutoff height
(Figures 4A, 4B).
20
170
295
400
480
18 2
135
235
315
375
16
105
180
240
285
Merchantable
height is 2
16-foot logs
Figure 4B. Reading merchantable height from a scale stick.
Estimating the Volume of a Standing Tree Using a Scale (Biltmore) Stick
Cutoff point
Line of sight
Line of sight
Stand 66 feet from the tree and hold the scale stick
vertically, 25 inches from your eye.
Stump height
12 inches –>
Figure 3. Measuring diameter with a scale stick.
Line of sight
25" distance
Line of sight
Zero end of stick
Eye
Stump height
28 30 36
345
615
850
1025
520
935
1305
1590
32
405
720
990
1200
460
825
1150
1400
34 38 40
730
1330
1870
2295
590
1065
1485
1815
655
1185
1670
2040
STAND 66 FEET FROM TREE. HOLD STICK VERTICALLY 25 INCHES FROM EYE. SIGHT THIS END AT STUMP HEIGHT
1
Merchantable
height is two
16-foot logs
Crop Tree Management in North Carolina 5
TREE ESTIMATE STICK
INTERNATIONAL RULE FC 78
HOLD STICK LEVEL AGAINST TREE 25 INCHES FROM
EYE AND 4 1/2 FEET ABOVE GROUND ON UPHILL SIDE
10
3
6 8
20
30
35
60
75
Diameter of Tree (Inches) 4
Number of 16-Foot Logs
4
1 16-Foot Log
2 16-Foot Logs
3 16-Foot Logs
4 16-Foot Logs
Which Price Do You Use?
Timber prices per board foot vary, based on which log rule is used to estimate timber volume.
Here are conversion factors for the various log rules:
Log Rule Conversions (Dollar Values)
Doyle to Scribner (26% difference) 0.75 Doyle to Scribner
Scribner to Doyle 1.33 Scribner to Doyle
Doyle to International ¼-inch (39% difference) 0.62 Doyle to International ¼-inch
International ¼-inch to Doyle 1.60 International ¼-inch to Doyle
Scribner to International ¼-inch (20% difference) 0.83 Scribner to International ¼-inch
International ¼-inch to Scribner 1.20 International ¼-inch to Scribner
For Example: You know that pine sawtimber is selling for $300 per 1,000 board feet
(Scribner log rule). What is the price equivalent for the International ¼-inch log rule?
$300 per 1,000 board feet (Scribner log rule) X 0.83 = $249 per 1,000 board feet
(International ¼-inch log rule)
Estimating Volume
To estimate the board-foot volume of a tree using the volume table (International ¼-inch rule)
imprinted on the scale stick, you need an estimate of the tree’s DBH and merchantable height.
With these two measurements, the board-foot volume of the tree is estimated by reading first the
tree’s DBH and then the number of 16-foot logs (Figure 5). For example, a tree that is 10 inches
DBH with a merchantable height of two 16-foot logs would have a volume of 60 board feet,
International ¼-inch rule. See the box below for instructions on converting to Doyle or Scribner.
Figure 5. Estimating volume using the volume table
imprinted on the scale stick.
Woodland Owner Notes
Crop Tree Management in North Carolina 6
Prepared by
Robert E. Bardon, Extension Forestry Specialist
Published by
NORTH CAROLINA COOPERATIVE EXTENSION SERVICE
4/02—5M—DSB WON-05
E02-39054
Things to Remember
• Seek professional forestry advice
before selling your timber.
• The products that could be made
from a tree vary based on minimum
size requirements and tree quality.
• In general, product value increases
with tree size.
• Timber prices differ, based on which
log rule is used.
• Tree volume estimates vary, based
on which log rule is used.
• When reviewing tree volume and
prices, be sure that the price used
to estimate value is for the log rule
used to estimate volume.
• To ensure accuracy, hold the stick
25 inches from your eye when mea-suring.
• To measure tree height correctly,
stand 66 feet from the tree.
5,000 copies of this public document were printed at a cost of $1426.00 or $.29 per copy.
Woodland Owner Notes